The present invention relates to post driving apparatus or reconfigurable post driving apparatus (i.e. which may have other applications, e.g. as a ground spiker).
In my New Zealand Patent Specification No. 174807 (now ceased) there is disclosed an early variant of the KING HITTER(trademark) post driver that is currently manufactured and sold by my company Fairbrother Industries Limited. The full content of the aforementioned New Zealand Patent Specification No. 174807 and of the current brochures of this company in respect of the various KING HITTER(trademark) models is here included by way of reference.
By way of exemplification the drawings (FIGS. 1 through 4) of my aforementioned New Zealand Patent Specification No. 174807 are appended hereto as FIGS. 1 through 4. For a description of that product reference should be made to New Zealand Patent Specification No. 174807, the full content of which is hereby here incorporated by way of reference.
We have determined that the steel utilized for the upright beam or mast (hereafter xe2x80x9cbeamxe2x80x9d) that provides the guide for the monkey which is to strike the top of a post can over time be subject to fatigue resulting in ultimate breakage.
The present invention relates to readily available steel xe2x80x9cIxe2x80x9d beams being strengthened sufficiently (without introducing localised stresses that exacerbate the fatigue difficulty) over at risk regions and particularly adjacent the lower regions of the beam that hitherto have given rise to fatigue difficulties.
It is therefore to such a strengthened beam for a post driver or any variant thereof machines made using such a beam, their use and to related methods of strengthening such beams of post drivers that the present invention is directed.
In a first aspect the present invention consists in a beam for or of a post driver, being a steel xe2x80x9cIxe2x80x9d beam of a kind having a web and two flange pairs each separated from the other pair by the web""s lateral width, wherein a lower region of the xe2x80x9cIxe2x80x9d beam has been strengthened by the provision on at least one side of the web of a (lateral) web spanning member (preferably a plate) which is welded at each of its edges parallel to the longitudinal axis of the xe2x80x9cIxe2x80x9d beam into a flange of said xe2x80x9cIxe2x80x9d beam.
Preferably said plate or other spanning member is attached by welding only to a flange of said xe2x80x9cIxe2x80x9d beam of each of said flange pairs.
Preferably said welding is full seam or stitch welding.
Preferably a plate or other such spanning member is provided on each of the opposing sides of said web of the xe2x80x9cIxe2x80x9d beam (preferably similarly welded).
Preferably said lower region of the xe2x80x9cIxe2x80x9d beam is at and adjacent the adaption thereof for connection to a mounting of the post driver.
Preferably said adaption is adapted to provide a pivot mounting.
Preferably said adaption is an outstanding stub axle extending in a direction which includes the plane of said web.
More preferably said adaption is a pivot sleeve to act on a pin or axle from a mounting, the bore of such a sleeve preferably extending normal to the plane of said web and preferably without interrupting the xe2x80x9cIxe2x80x9d beam form itself.
In other less preferred forms such a sleeve can be provided in a different substantially lateral direction with respect to the xe2x80x9cIxe2x80x9d beam.
Preferably each flange pair or at least one flanged pair is strengthened by a longitudinally (of xe2x80x9cIxe2x80x9d beam) running reinforcement plate having been affixed thereto on a side or sides thereof remote from such web.
Preferably one such reinforcing plate is wider than the pair of flanges to which it is affixed (preferably by welding, eg; stitch welding) whilst the other is not.
Preferably the arrangement is substantially as hereinafter described.
Preferably the relative extents of the various strengthenings is substantially as hereinafter described with reference to any one or more of the accompanying drawings.
In still a further aspect the present invention consists in a post driver which utilises a beam reinforced to provide a beam in accordance with the present invention.
In yet a further aspect the invention consists in, a post driver, of a kind with a pivotally mounted beam,
characterised in that said beam is of a fabricated construction at least essentially of
a steel xe2x80x9cIxe2x80x9d beam of a kind having a web and two flange pairs separated by the web""s lateral width,
a first longitudinally running strengthening strip welded to the outside of one of said flange pairs,
optionally a second longitudinally running strip welded to the outside surface of the other flange pair, and
(on at least one side of the web) a spanning member between the flanges of the two pairs to reinforce the zone at which beam is pivot mounted, such a spanning member being welded only into each said flange.
Preferably there is similarly mounted a spanning member (e.g. plate) on each side of the web and each is similarly attached.
Preferably the pivot is in alignment with the web of said xe2x80x9cIxe2x80x9d beam.
Preferably said post driver is of a kind typified by the aforementioned New Zealand patent specification and/or a post driver of the KING HITTER(trademark) type (optionally with some of the variable characteristics of that range).